Timken36990Tapered Roller Bearing Cone – 7.0000 in Bore, 1.1875 in Cone Width, K Factor 1.33, Stamped Steel Cage, Case-Carburized Steel

Product Description

What this part is

A Timken 36990 single cone — the inner ring with its roller and cage assembly — from the imperial 36900 tapered roller bearing series. Cone only. The matching single cup is the Timken 36920. Bore is 7.0000 in (177.800 mm) and the inner ring width B is 1.1875 in (30.163 mm). With the 36920 cup fitted, the assembled bearing outside diameter is 8.9375 in (227.013 mm). The cage is stamped steel and the rings and rollers are case-carburized alloy steel.

Decoding the designation

36990 is the cone number within the 36900 series; 36920 is the cup number that shares its raceway angle and roller path. Timken also lists a 36920CD double cup for this series, which takes two 36990 cones in a two-row mounting. The 36990 designation carries no precision suffix, so no tolerance class is published for it — a Timken Class 2 part is written with an explicit -2 and a Class 3 part with a -3 or *3. The Caterpillar order number 6V-0663 refers to the same cone.

Load ratings and mounting factors

Per row, the dynamic radial load rating at one million revolutions (C1) is 47000 lbf (209000 N) and at ninety million revolutions (C90) is 12200 lbf (54200 N). The dynamic axial rating Ca90 is 9190 lbf (40900 N) and the static radial load rating C0 is 103000 lbf (458000 N). The K factor is 1.33. Lubrication life adjustment factors are G1 515, G2 241 and geometry factor Cg 0.143.

Shaft fitting data

The maximum shaft fillet radius cleared by the cone corner is 0.06 in (1.5 mm). Shaft backing shoulder diameter is 7.32 in (186 mm) at the frontface (da) and 7.4 in (188 mm) at the backface (db). Effective centre location is 0.5 in (12.7 mm). Cage location relative to the backface (Aa) is 0.08 in (2 mm) and relative to the frontface (Ab) is 0.1 in (2.5 mm). Cone weight is 13.27 lb (6.021 kg).

What these specs mean in practice

The K factor of 1.33 describes the ratio of radial to thrust capacity set by the raceway angle: a higher K means a shallower angle and a bearing biased toward radial load, a lower K a steeper angle carrying proportionally more thrust. At 1.33 the 36990 sits in the general-purpose band used for heavy radial duty with moderate thrust, which is why the series appears in axle, conveyor and heavy off-highway drive positions. Timken rates standard tapered roller bearings of this construction for continuous operation from −54 °C to 120 °C, with oil or grease lubrication.

Quantity and configuration

One piece, one cone with its rollers and cage. Single row, straight bore, open with no seal or shield. Tapered roller bearings of this type are usually mounted in opposing pairs on a shaft so that the pair locates axially in both directions.

Interchange guidance

The 36990 cone number is used directly by Bower and NTN. Caterpillar 6V-0663 is the same cone under a machine builder’s number. The 36920 single cup and the 36920CD double cup are the mating outer races for this cone and are separate parts — a cup is a raceway ring with no bore and no seal, and it is ordered by its own number.